Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 031c1267f89b0ab3…

MALICIOUS

Office (OLE) / .XLS

231.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 3ab216a24e3bfe634896d87c864728d7 SHA-1: a841d49d7a4b915aabc757c2ecc38c5182ce9664 SHA-256: 031c1267f89b0ab386db4a1158a98984cf2d9bd1d72051a6a67bf37807e4aa17
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic

The sample is an Excel 4.0 (XLM) macro-enabled spreadsheet. It contains an Auto_Open macro that attempts to evade environment checks. The document body text is a lure to encourage users to enable content, which would trigger the malicious macro. The macro itself is designed to execute dangerous functions and potentially download a second-stage payload.

Heuristics 4

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • XLM Auto_Open environment-evasion HALT gate high OLE_XLM_ENVIRONMENT_EVASION_HALT
    Excel 4.0 macro sheet auto-executes multiple GET.WORKSPACE / GET.WINDOW environment checks and halts execution when the host does not match the expected user environment. This is a common sandbox-evasion pattern in XLM malware and is stronger than a bare XLM macro-sheet indicator.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
0461c09f636a03b391e3007de99f87abe2d5108f66b1899e341ccf139ccc8ddc
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 330352 bytes